1. Field of the Invention
The invention relates to a drive device for the motorized actuation of a functional element of a motor vehicle, in particular for opening and closing a top of a convertible. The drive device has an electric motor with a motor shaft. A worm shaft of a worm gearing has one end connected to the motor shaft. A radial bearing receives the other end of the worm shaft.
2. Description of the Related Art
Drive devices of this type are used in vehicle manufacturing as servo motors for a very wide variety of purposes, for example for opening and closing a top of a convertible, for seat adjustments, steering column adjustments, window openers, sliding roofs or the like. A drive device of this type has a worm gearing connected downstream of the electric motor and advantageously has small dimensions. The worm gearing is self-locking, and large forces can be transmitted via the worm gearing.
The electric motor in a drive device of this type has a motor shaft mounted twice in the radial direction and axial direction of an electric motor housing. The worm shaft is connected to the motor shaft. Thus, an additional radial mounting of the worm shaft is required with defined compensation for tolerances in the region of the radial bearing.
DE 10 2010 053 278 A1 discloses such a drive device used, for example, in conjunction with a top of a convertible. The electric motor is designed as a brushless direct-current motor. An end of a spindle that faces away from the brushless direct-current motor is mounted in a radial bearing that can absorb reaction forces of the driven system. A radial bearing also may be at the other end of the spindle.
DE 297 02 525 U1, EP 1 334 296 B1 and DE 42 10 302 C2 show a drive device with an electric motor and a worm shaft that is drivable by said drive device and with means for compensating for a length tolerance of the worm shaft.
DE 298 15 858 U1 describes a plastics plain bearing for mounting a shaft in a bearing body and in a plastics housing receiving the bearing body. The bearing body is fixable axially by inwardly protruding projections.
DE 911 196 pushes tolerance compensating rings onto plain bearing bushes to compensate for manufacturing tolerances in the radial direction.
It is the object of the invention to develop a drive device of the type described above that can compensate for tolerances in the region of the radial bearing.